United States Environmental Protection Agency
Solid Waste and Emergency Response (5306W)
EPA530-F-97-043
October 1997
www.epa.gov
INNOVATIVE USES OF COMPOST EROSION CONTROL, TURF
REMEDIATION, AND LANDSCAPING
Compost has been viewed as a valuable soil amendment
for centuries. Most people are aware that the use of compost
is an effective way to improve plant growth. Compost-
enriched soil can also reduce erosion, alleviate soil
compaction, and help control disease and pest infestation in
plants. These beneficial uses of compost can increase
healthy plant production, help save money, reduce the use of
chemical fertilizers, and conserve natural resources.
Compost used for a specific purpose or with a
particular soil type works best when it is tailor-made or
specially designed. For example, compost that is intended to
prevent erosion might not provide the best results when used
to alleviate soil compaction, and vice versa. Technical
parameters to consider when customizing a compost mixture
include maturity, stability, pH level, density, particle
size, moisture, salinity, and organic content, all of which
can be adjusted to fit a specific application and soil type.
COMPOST TECHNOLOGY TO CONTROL EROSION
According to the U.S. Department of Agriculture, the
United States loses more than 2 billion tons of topsoil
through erosion each year. Erosion occurs when wind and rain
dislodge topsoil from fields and hillsides. Stripped of its
valuable top layer, which contains many essential nutrients,
the soil left behind is often too poor to sustain good plant
growth. Eroded topsoil can also be carried into rivers,
streams, and lakes. This excess sediment, sometimes
containing fertilizers or toxic materials, threatens the
health of aquatic organisms. It can also compromise the
commercial, recreational, and aesthetic value of water
resources. As a result, preventing erosion is essential for
protecting waterways and maintaining the quality and
productivity of soil.
CONTROLLING EROSION IN CONSTRUCTION AND ROAD BUILDING
Erosion is a naturally occurring process; however, it
is often aggravated by activities such as road building and
new construction. At the beginning of some construction
projects, all vegetation and topsoil is removed, leaving the
subsoil vulnerable to the forces of erosion. On steep
embankments along roads and highways, compost can be more
effective than traditional hydromulch at reducing erosion
and establishing turf because compost forms a thicker, more
permanent growth due to its ability to improve the
infrastructure of the soil.
Depending on the length and height of a particular
slope, a 2- to 3-inch layer of mature compost, screened to
1/2 to 3/4 of an inch and placed directly on top of the
soil, has been shown to control erosion by enhancing planted
or volunteer vegetation growth. On steep slopes, berms
(mounds) of compost at the top or bottom of slopes can be
used to slow the velocity of water and provide additional
protection for receiving waters. Because of its ability to
retain moisture, compost also helps protect soil from wind
erosion and during droughts.
Controlling Erosion in Road Construction
The Federal Highway Administration (FHWA), of the U.S.
Department of Transportation and the U.S. Environmental
Protection Agency, recently conducted an erosion control
demonstration project that compared mature yard trimmings
compost that met FHWA specifications with hydromulch, a
substance traditionally used for controlling erosion on
roadside embankments. The purpose of the study was to
determine the effectiveness of mature yard trimmings compost
compared with hydromulch in establishing Fescue grass.
The project site was at a newly constructed
intersection in suburban Washington, DC. Two embankments
with steep slopes were selected. The first embankment had a
2 to 1 slope; the second had a 3 to 1 slope. A
hydromulch/fertilizer treatment also was applied to a
section of each of the slopes. Adjacent to these sections,
2-1/2 inches of mature yard trimmings compost was spread. On
the 2 to 1 slope, a small amount of fertilizer was also
applied, while the 3 to 1 slope was left unfertilized.
Fescue grass seed was added and covered with a thin layer of
compost to conceal the seed from birds.
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Results of the project revealed that compost used alone
produced better results than either of the areas treated
with hydromulch or the area treated with compost and
fertilizer. While the areas with the hydromulch/fertilizer
combination showed quick initial vegetative growth, the
areas treated with only compost persevered within 6 months,
outperforming the traditional method by establishing a
thick, healthy vegetative cover. The growth in the compost/
fertilizer plot was superior to that found in the
hydromulch/fertilizer plots. A possible explanation for
compost alone outperforming the area treated with compost
and fertilizer is that chemical fertilizers often increase
soil salinity, which in turn could negatively affect the
beneficial microorganisms in compost and inhibit the
establishment of healthy grasses.
USING COMPOST TO REMEDIATE TURF GRASSES
Providing safe, uniform playing surfaces for
recreational activities, such as golf, football, soccer, and
other field sports, requires intensive turf management.
Recreational turf grasses are subjected to extensive wear
and tear, making them difficult to manage and highly
susceptible to turf diseases, pests, and soil compaction. To
address these problems, turf managers traditionally use a
combination of fertilizers, pesticides, fungicides, and
aeration techniques that usually result in high costs and
potential for negative environmental impacts.
Some turf managers are now using compost to replace
peat moss in their topdressing applications based on its
proven success in suppressing plant disease. Compost, when
properly formulated, unlike peat moss, is teeming with
nutrients and microorganisms that stimulate turf
establishment and increase its resistance to common turf
diseases, such as snow mold, brown patch, and dollar spot.
For example, after 3 years of using compost as a
topdressing, the Country Club of Rochester, New York, has
nearly eliminated the need for fungicide applications for
such diseases.
Alleviating Soil Compaction
Soil compaction is another persistent landscape
management problem, particularly in areas of heavy traffic,
such as parks, zoos, golf courses, and athletic playing
fields. Compacted soil impedes healthy turf establishment by
inhibiting the movement of air, water, and nutrients within
the soil. Bare soil, weeds, increased runoff, and puddling
after heavy rains are the most obvious signs of a soil
compaction problem.
Traditional methods for alleviating soil
compaction--aeration, reseeding, or complete resodding--are
labor-intensive and expensive, and provide only short-term
solutions. Some turf managers are starting to use compost
and compost amended with bulking agents, such as aged crumb
rubber from used tires or wood chips, as cost-effective
alternatives. Incorporating tailor-made composts into
compacted soils improves root penetration and turf
establishment, increases water absorption and drainage, and
enhances resistance to pests and disease. Using tailored
compost can also significantly reduce the costs associated
with turf management. Research conducted at a U.S. Air Force
golf course in Colorado Springs, Colorado, for example,
indicated that turf grown in areas improved with tailored
compost required up to 30 percent less water, fertilizer,
and pesticides than turf treated conventionally.
Greening the Links
The U.S. Army Golf Course Operations Division at Fort
George Meade, Maryland, and the U.S. Environmental
Protection Agency began a 3-year pilot demonstration in 1995
to determine the effectiveness of compost amended with crumb
rubber in alleviating soil compaction, erosion, and turf
disease problems. The golf course superintendent estimates
that using compost technology would save nearly $50,000 a
year in maintenance costs.
Mature yard trimmings compost amended with crumb rubber
was incorporated into compacted soils at 13 different
locations around the two golf courses. Many of the selected
sites included areas adjacent to, or at the end of golf cart
paths, on slopes surrounding greens, or in tee boxes. These
sites were selected because of their susceptibility to
compaction and erosion caused by heavy traffic and water
runoff. The compost mixture was tilled into the soil to a
depth of about 3 to 5 inches and then uniformly seeded. To
act as a control, one of the plots was amended only with
crumb rubber.
In the first year of the pilot, course operators
reported that healthy, green turf grass took hold at most of
the sites, with no signs of compaction or erosion. Results
were particularly impressive in eroded ditches along cart
paths. The areas treated with the compost mixture showed
full growth of turf grasses and total abatement of erosion,
whereas the plot amended only with crumb rubber showed few
signs of improvement.
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What Are the Benefits of Using Compost?
Soil Enrichment:
* Adds organic bulk and humus to regenerate poor
soils.
* Helps suppress plant diseases and pests.
* Increases soil nutrient content and water
retention in both clay and sandy soils.
* Restores soil structure after reduction of natural
soil microbes by chemical fertilizer.
* Reduces or eliminates the need for fertilizer.
* Combats specific soil, water, and air problems.
Pollution Remediation:
* Absorbs odors and degrades volatile organic
compounds.
* Binds heavy metals and prevents them from
migrating to water resources or being absorbed by
plants.
* Degrades, and in some cases, completely eliminates
wood preservatives, petroleum products,
pesticides, and both chlorinated and
nonchlorinated hydrocarbons in contaminated soils.
Pollution Prevention:
* Avoids methane production and leachate formation
in landfills by diverting organics for composting.
* Prevents pollutants in stormwater runoff from
reaching water resources.
* Prevents erosion and silting on embankments
parallel to creeks, lakes, and rivers.
* Prevents erosion and turf loss on roadsides,
hillsides, playing fields, and golf courses.
Economic Benefits:
* Results in significant cost savings by reducing
the need for water, fertilizers, and pesticides.
* Produces a marketable commodity and a low-cost
alternative to standard landfill cover and
artificial soil amendments.
* Extends municipal landfill life by diverting
organic materials from the waste stream.
* Provides a less costly alternative to conventional
bioremediation techniques.
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Using amended compost can significantly reduce the
costs associated with turf management.
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USING COMPOST IN LANDSCAPING ACTIVITIES
Supplies of high-quality, low-cost top-soil are
declining, particularly in urban areas where the demand is
greatest. Compost is, therefore, becoming particularly
important in applications requiring large amounts of
topsoil. Increasingly, compost is being used as an
alternative to natural topsoil in new construction,
landscape renovations, and container gardens. Using compost
in these types of applications is not only less expensive
than purchasing topsoil, but it can often produce better
results when trying to establish a healthy vegetative cover.
After a lawn or garden has been established,
maintaining it can be a challenge for both home gardeners
and commercial landscape contractors. While aeration,
topdressing, and chemical fertilizer applications are some
of the techniques commonly employed in landscaping
applications, compost can be a successful alternative. When
used as a topdressing, or periodically tilled into the soil,
compost can stimulate plant growth, reduce pests and plant
infestation, and improve soil structure.
Compost is also an effective landscaping mulch. Placed
over the roots of plants, compost mulch conserves water and
stabilizes soil temperatures. In addition, compost mulch
keeps plants healthy by controlling weeds, providing a slow
release of nutrients, and preventing soil loss through
erosion. Landscapers and gardeners also use compost as mulch
because its dark, rich color accents the vibrant colors of
flowering plants.
Landscaping Constitution Gardens
In 1973, the U.S. National Park Service used a compost
mixture made of digested sewage sludge, wood chips, leaf
mold, and a small amount of topsoil to transform a badly
compacted 40-acre tract of land located in Washington, DC,
into a landscaped park. This project is one of the earliest
successful large-scale landscaping applications using
compost.
The original plans for the park renovations included
planting azalea beds and thousands of annuals around a
6-acre lake. However, the site assessment revealed that the
soil was almost as hard as concrete, with little pore space
for plant roots and for water infiltration. The soil was too
low in nutrients for healthy plant growth. In addition, the
water table was high, causing flooding and root rot in
existing plants.
Park Service staff spread over 9,400 cubic yards of the
compost mixture over the site. Fertilizer, woodchips, and
seed were added, and the soil was tilled to a depth of 2
feet. Impressed by the hardiness and beauty of a stand of
hardwood trees along the area's western edge, Park Service
staff decided to plant several varieties of native trees
rather than the planned azalea beds. Data taken 3 years
after the project ended indicated that most of the nearly
2,000 trees initially planted had flourished in the park.
The compost use in this project not only improved the
quality of the existing soil, but also saved taxpayers over
$200,000. Park Service staff also reviewed other options for
remediating the soil at the park, including the purchase of
topsoil to spread over the existing poor soil. If the Park
Service staff had chosen to use topsoil, the cost of the
project would have doubled.
Using Compost for Rooftop Gardens
Several years ago, officials at Pace School in
Pittsburgh, Pennsylvania, proposed building a playground and
garden for their students. They soon discovered, however,
that the only space available was on the school's roof, so
they designed a unique rooftop garden.
Plans for the garden included building large, 6-foot
deep planters. Before the planters were constructed, several
important factors had to be taken into consideration. The
planter mix used had to be light enough for the roof to
withstand the weight, yet dense enough to prevent rapid
evaporation caused by the wind and summer heat. In addition,
the planter mix had to be able to endure freezing
temperatures in winter, and provide adequate drainage to
prevent the planters from overflowing during rainstorms.
To meet these special needs, the school decided to use
a tailor-made mature compost blend, chosen because its bulk
density is much lighter than soil-based mixes. The compost
mix is also extremely absorbent, maintains good drainage,
and protects plant roots from climatic fluctuations.
A local compost producer tailor-made a mature yard
trimmings compost mixture to meet the project's
specifications. A layer of polystyrene packaging peanuts was
placed in the bottom of each planter box to enhance
drainage, and a 5-foot layer of the compost mixture was
placed on top.
Four years after the project began, the school
continues to use its rooftop garden for a number of
activities, including teaching science classes and gardening
methods. The compost has performed very well as a growing
medium and continues to produce beautiful, healthy plants
that both the students and teachers can enjoy.
Using Compost in Landscape Maintenance
Each year, millions of people visit Point State Park in
Pittsburgh, Pennsylvania. Heavy traffic and 12 continuous
years of chemical fertilizer applications caused the park's
grassy areas to become increasingly compacted, eroded, and
depleted of vital nutrients.
After considering several options, park officials
decided to aerate the grassy areas and apply a special blend
of mature yard trimmings compost and fire calcined clay.
This compost mixture was designed to alleviate compaction,
add nutrients to the soil, and to improve water-holding
capacity. Workers spread a 1/4-inch topdressing of the
compost mixture and then uniformly applied grass seed. Soon
after the compost was applied, park officials noted that the
turf was healthier and that the soil no longer exhibited
signs of compaction.
References
Cazenas, P. and R.E. Green. 1997. Erosion prevention on
steep enbankments by mature yard trimmings compost compared
to hydromulch. Washington. (In manuscript).
Castagnero, C. 1996. Conversation with Dr. R.E. Green.
Establishment of Pace School Rooftop Garden with the use of
tailored, mature compost. Pittsburgh.
__________. 1996. Conversation with Dr. R.E. Green. The use
of mature compost in state park landscape maintenance.
Pittsburgh.
Federal Highway Administration. 1996. Standard
Specifications For Construction of Roads and Bridges on
Federal Highway Projects, U.S. Department of Transportation.
FP-96, Sec. 713, p.719.
Lincoln, T. Rebound--the New Product Turf Managers Dream
About, Jai Tire Industries. Denver.
Nelson, E.B. 1992. The biological control of turf-grass
diseases. Golf Course Management. April: 78-90.
Patterson, J. 1994. The successful remediation of
severely-compacted soil at the U.S. Constitution Gardens.
Paper presented at a workshop in Washington.
Wilkinson, J.F. 1992. Applying compost to the golf course.
Golf Course Management. April: 78-90.
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